Metabolic disturbances induce malignant heart arrhythmias in rats

Metabolic disturbances are considered to condition the occurrence of malignant heart arrhythmias and negatively influence the chances of a patient to survive. To test this assumption, a model of metabolic syndrome was selected in which rats were receiving a diet resembling that of the westernized population.

Metabolic syndrome is a comorbidity of major cardiovascular risk factors (dyslipidemia, hypertension, impaired glucose tolerance or insulin resistance, diabetes mellitus, and obesity), all facilitating cardiovascular complications leading to morbidity and mortality of patients.

Hearts were isolated and perfused according to Langendorff. Global ischemia was induced in the hearts and arrhythmia occurrence in reperfusion was monitored. All hearts were stimulated with the electro-cardio-stimulator to test the electrical inducibility of heart arrhythmia.

Isolated hearts from rats with the metabolic syndrome were more susceptible to ventricular arrhythmias. The high-fat diet increased the occurrence of malignant heart arrhythmias in rats with metabolic syndrome to an even greater extent. All subjects with metabolic syndrome were sensitive to ventricular tachyarrhythmia with significantly decreased threshold to its induction in cardio-stimulation.

These results indicate that metabolic syndrome patients may be more sensitive to the occurrence of malignant heart arrhythmias following myocardial infarction or other heart diseases (Tab. 1, Fig. 2, Ref. 34).